Visual quality is an important aspect of the user experience in many media applications. Furthermore, in compression/decompression (codec) systems, visual quality may be primarily based on the compression format used. For example, a video encoder compresses video information so that more information can be sent over a given bandwidth or stored in a given memory space, etc. The compressed signal or data may then be decoded via a decoder that decodes or decompresses the signal or data for display to a user.
Video conferencing is an important application for video encoding. The video captured in video conferencing applications usually has different characteristics from other common video applications such as broadcast TV programming, and the like. Many conventional video encoding solutions ignore the unique characteristics of video conferencing, and as a result the compression efficiency and/or visual quality is not high. In one approach for example, a constant quantization parameter (QP) is used. Transform coefficients obtained via an encoding technique such as the H.264/MPEG-4 Advanced Video Coding (AVC) standard or the High Efficiency Video Coding (HEVC) standard or the like may be quantized using the constant QP. A larger QP value results in greater compression at the cost of lower quality, while lower QP values achieve greater visual quality at the cost of a reduced compression rate. Such constant QP approaches may not provide adequate visual quality for a video conferencing user. Furthermore, such constant QP approaches may be wasteful in compressing certain portions of video sequences (either spatially within a video frame or temporally across video frames).
As such, existing techniques for determining QP may not be satisfactory. As video conferencing end user expectations continue to increase, techniques for determining QP, and systems capable of performing such determinations become more advantageous in the market place.